Modification of keratinic fibers with ethylenically unsaturated compounds

ABSTRACT

KERATINIC TEXTILE MATERIALS ARE REACTED WITH ETHYLENICALLY UNSATURATED COMPOUNDS WHICH, IN POLYMER OR COPOLYMER FORM, HAVE A GLASS TRANSITION TEMPERATURE IN EXCESS OF 50*C. TO PRODUCE A MATERIAL WHICH MAY BE SET UNDER HEATING CONDITIONS IN A DESIRED CONFIGURATION WHICH IS DURABLE TO THE EFFECTS OF WETTING WITH WATER.

Unitcd States Patent Oflice US. Cl. 8-1275 4 Claims ABSTRACT OF THEDISCLOSURE Keratinic textile materials are reacted with ethylenicallyunsaturated compounds which, in polymer or copolymer form, have a glasstransition temperature in excess of 50 C. to produce a material whichmay be set under heating conditions in a. desired configuration which isdurable to the eifects of wetting with water.

This case is a continuation of US. application Ser. No. 242,638, filedDec. 6, 1962, and now abandoned.

This invention relates to a novel process for producing keratin fibershaving a high degree of settability and crease retentivity and tofabrics and garments produced therefrom.

Keratin fibers, particularly wool fibers, are used extensively in theproduction of garments. These garments have excellent insulating andaesthetic properties, but in some instances, such as after wetting, thegarments lose their otherwise neat appearance. This difliculty has beengenerally overcome by various processes involving treatment of thegarments, or of the fabric from which the garment is made, with variousreducing agent systems. These processes invariably involve an increasedcost in the garment, due to the extensive process control requirementson the part of either the fabric manufacturer or garment-maker. Inaddition, the configuration set in the garment by one of the prior arttechniques is substantially permanent and cannot be altered withoutextensive treatment.

For example, once trousers are creased in accordance With prior artsetting techniques, that crease tends to remain in the trousers. Shouldthe trousers be creased again without chemical treatment, as by acommercial dry cleaner, this second crease, though not durable, alsowould be visible along with the initial crease, giving an undesirabledouble-creased appearance.

It is an object of this invention to treat keratin fibers in such amanner as to impart thereto a high degree of settability and acorrespondingly high degree of retention of the configuration in whichthe fibers are set.

It is a further object of this invention to produce yarns,

fabrics, and garments from such treated keratin fibers,

which yarns, fabrics and garments will have a similar settability andcapacity to retain the set configuration.

Another object of this invention is to produce keratin fibers, andyarns, fabrics and garments therefrom, which can be set in any givenconfiguration with the further capability of having that configurationreadily altered to other configurations as desired.

These objects are accomplished in accordance with this invention whichcomprises reacting keratin fibers, preferably in the form of arelatively lose mass, with a particular class of ethylenicallyunsaturated compounds and then forming these fibers into a fixedstructure, such as yarns, fabrics and/or garments, whereby saidstructure may be set in a given configuration which will be durable towetting.

3,583,855 Patented June 8, 1971 By settability as used herein is meantthe capacity of a fiber to be set in a predetermined configuration whichwillbe retained even after prolonged exposure to wet conditions. Bycrease retentivity as used herein is meant the ability of a. keratinfiber to retain a crease or pleat after prolonged exposure to wetconditions.

Wool fabrics have been reacted with a wide variety of ethylenicallyunsaturated compounds, generally to impart to such fabrics a resistanceto felting shrinkage effects. There has been no realization heretofore,however, that a certain class of ethylenically unsaturated compounds maybe reacted with keratin fibers so that fixed structures, such as yarns,fabrics and/or garments produced therefrom, may be durably. set in anygiven configuration, e.g., flat, creased, pleated or otherwise, underconditions of heat and pressure; These configurations, furthermore, maybe readily altered to other configurations as desired under the sameconditions of heat and pressure. Generally, the temperature of settingexceeds the glass transition temperature of the compound systemutilized.

v The class of ethylenically unsaturated compounds suitable for use inaccordance with this invention includes those compounds which, inpolymer form, have a glass transition temperature in excess of about 50C., preferably above about C. Copolymers containing small amounts'ofother compounds having lower glass transition temperatures may beutilized, although the effect will generally be considerably minimizedin this instance.

- The glass transition temperature is a well-known property and is thetemperature at which a sheet of a polymer is transformed from aglass-like solid state to a softened state. Above the glass transitiontemperature, the volume of the sheet increases more rapidly with anincrease in temperature, The point at which this volume increase beginsmay be readily determined in a plot of volume verses temperature. Theseglass transition temperatures may be readily determined by standardA'LS.T.M. heat deflection temperature measurements, e.g., A.S.T.M.Designation D648-45T, issued 1941, revised 1944, 1945.

Among the suitable compounds, there are included acrylamides and themonomeric or low polymeric forms of N-dialkyl acrylamides, such asN,N-dimethyl, -diethyl, -dipropyl, -dibutyl, -dihexyl, -dioctyl, etc,acrylamides; N-(p-anisyl) methacrylamide, N-(p-chlorophenyl)methacrylamide, N-phenyl methacrylamide, N-ethylmethylmethacrylamide,N-methylmethacrylamide, N-(p-tolyl) methacrylamide and the like;unsaturated acids and anhydrides, such as acrylic, methacrylic,ethacrylic, propacrylic, chloroacrylic, bromoacrylic, aconitic,itaconic, maleic, crotonic, fumaric citraconic and the like; the phenyl,benzyl, phenylethyl, etc., esters of the aforementioned acids; vinylaromatic compounds, such as styrene and methylstyrenes, such asm-methylstyrene, o-methylstyrene, p-methylstyrene and dimethylstyrenes,such as 2,5-dimethylstyrene; halogenated styrenes, such asmbrornostyrene, p-bromostyrene, p-iodostyrene, pentachlorostyrene,a,,8,,3-trifluorostyrene, 2,5-bis(trifiuoror'nethyl) styrene,3-trifluoromethyl styrene, dichlorostyrene, and the like; the variouscyanostyrenes; the various methoxystyrenes, e.g., p-methoxystyrene;vinyl naphthalenes, etc., e.g., 4-chloro-1-vinylnaphthalene,6-chloro-2-vinylnaphthalene; vinyl halides, e.g., vinyl chloride,bromide, etc.; itaconic and maleic diesters containing a singlegrouping, e.g., the dimethyl, diethyl, di-fl-chloroethyl, diethylchloro,diisopropyl, dipropyl, dibutyl, diisobutyl, dinonyl and other saturatedaliphatic monohydric alcohol diesters, e.g., diphenyl itaconate,dibenzyl itaconate, di-

(phenylethyl) itaconate, etc., and corresponding maleates, and methylmethacrylate; nitriles containing a single grouping, e.g.,acrylonitrile, methacrylonitrile, and the like; and similar compoundsreacted with ethylenically unsaturated cross-linking agents, e.g.,divinylbenzene, glycidyl methacrylate and the like.

Preferred compounds from the above class include acrylonitrile (glasstransition temperature ca. 95 C.), styrene (ca. 100 C.) dichlorostyrene(ca. 130 C.), methyl methacrylate (ca. 105 C.), vinyl chloride (ca. 80C.) and copolymers containing a sufficient amount of such compounds,including copolymers containing compounds having glass transitiontemperatures below 50 C., to provide a copolymer having a glasstransition temperature above about 50 C., e.g., styrene/acrylonitrile(ca, 110 C.), styrene/fumaronitrile (ca. 125 C.),styrene/dichlorostyrene (ca. 110 C.) vinyl chloride/ vinyl acetate (ca.60 C.) vinyl chloride/vinylidene chloride (ca. 60 C.) styrene/butylacrylate 90/10 (ca. 77 C.), styrene/butyl acrylate 85/15 (ca. 67 C.)methyl methacrylate/ethyl acrylate 80/20 (ca. 71 C.) and the like.

Of the above compounds, acrylonitrile, styrene and methyl methacrylateare highly preferred for availability, cost and performance.

While some improvement is obtained at any significant pickup of theabove compounds, e.g., above about by weight, the desired improvement isobtained to a significant level only at pickup in excess of about 50% byweight of the above compounds.

This class of ethylenically unsaturated compounds can be reacted withkeratin fibers through a number of wellknown processes. For example,keratin fibers may be reacted with the desired compounds in the presenceof a catalyst or initiator system for inducing polymerization of thecompounds. Among such systems, there are included azo catalyst, such asazobisisobutyronitrile, as well as irradiation under the influence ofhigh energy fields, including the diverse actinic radiations, such asultraviolet, X-ray and gamma radiations, as well as radiations fromradioactive materials such as cobalt-60.

In general, however, it is pr'eferred that the reaction with theparticular class of ethylenically unsaturated compounds be conducted inthe presence of a redox catalyst system, i.e., a catalyst systemcomposed of a reducing agent and an oxidizing agent initiator. Althoughthe catalytic mechanism is not completely understood, it is believedthat the interaction of these agents provides free radicals which causepolymerization of the compounds, which preferably are in monomeric orlow polymeric form, onto or into the keratin fibers.

The reducing agent may be an iron compound, such as the ferrous saltsincluding ferrous sulfate, acetate, phosphate, ethylenediaminetetra-acetate; metallic formaldehyde sulfoxylates, such as zincformaldehyde sulfoxylate; alkali-metal sulfoxylates, such as sodiumformaldehyde sulfoxylate; alkali-metal sulfites, such as sodium andpotassium bisulfite, sulfite, metabisulfite or hydrosulfite; mercaptanacids, such as thioglycollic acid and its water-soluble salts, such assodium, potassium or ammonium thioglycollate; mercaptans, such ashydrogen sulfide and sodium or potassium hydrosulfide; alkyl mercaptans,such as butyl or ethyl mercaptans and mercaptan glycols, such asbeta-mercaptoethanol; alkanolamine sulfites, such as monoethanolaminesulfite and mono-isopropanolamine sulfite; manganous and chromous salts;ammonium bisulfite, sodium hydrosulfide, cysteine hydrochloride, sodiumthiosulfate, sulfur dioxide, sulfurous acid and the like, as well asmixtures of these reducing agents. In addition, a salt of hydrazine maybe used as the reducing agent, the acid moiety of the salt 4 beingderived from any acid, such as hydrochloric, hydrobromic, sulfuric,sulfurous, phosphoric, benzoic, acetic and the like.

Suitable oxidizing agent initiators for use in the redox catalyst systeminclude inorganic peroxides, e.g., hydrogen peroxide, barium peroxide,magnesium peroxide, etc., and the various organic peroxy catalysts,illustrative examples of which are the dialkyl peroxides, e.g., diethylperoxide, dipropyl peroxide, dilauryl peroxide, dioleyl peroxide,distearyl peroxide, di(tert.-butyl) peroxide and di-(tert.-amyl)peroxide, such peroxides often being designated as ethyl, propyl,lauryl, oleyl, stearyl, tert.-butyl and tert.-amyl peroxides; the alkylhydrogen peroxides, e.g., tert.-butyl hydrogen peroxide (tert.-butylhydroperoxide), tert.-amyl hydrogen peroxide (tert.-amyl hydroperoxide),etc.; symmetrical diacyl peroxides, for instance peroxides whichcommonly are known under such names as acetyl peroxide, propionylperoxide, lauroyl peroxide, stearoyl peroxide, malonyl peroxide,succinyl peroxide, phthaloyl peroxide, benzoyl peroxide, etc.; fatty oilacid peroxides, e.g., coconut oil acid peroxides, etc.; unsymmetrical ormixed diacyl peroxides, e.g., acetyl benzoyl peroxide, propionyl benzoylperoxide, etc.; terpene oxides, e.g., ascaridole, etc.; and salts ofinorganic peracids, e.g., ammonium persulfate, potassium persulfate,sodium percarbonate, potassium percarbonate, sodium perborate, potassiumperborate, sodium perphosphate, potassium perphosphate, etc.

Other examples of organic peroxide initiators that can be employed arethe following: tetralin hydroperoxide, tert.-butyl diperphthalate,cumene hydroperoxide, tert.-butyl perbenzoate, 2,4-dichlorobenzoylperoxide, urea peroxide, caprylyl peroxide, p-chlorobenzoyl peroxide,2,2-bis(tert.-butyl peroxy) butane, hydroxyheptyl peroxide and thediperoxide of benzaldehyde.

The above oxidizing agent initiators, particularly the salts ofinorganic peracids, may be utilized alone to initiate the reaction,although faster reactions at lower temperatures may be conducted whenthe oxidizing agent is combined with a reducing agent to form a redoxcatalyst system. Ferric salts can be used as oxidizing agents and form aredox catalyst system with hydrogen peroxide, in which case the peroxidefunctions as a reducing agent.

The reaction between keratin fibers and ethylenically unsaturatedcompounds most readily takes place in thepresence of water. Thisgenerally presents no problem since only small amounts are necessary forthis improvement and since the catalyst components land/or monomers aregenerally applied to the fibers in an aqueous medium. If the substrateis dry at the time of treatment, the reaction rate will be slower.Consequently, it is preferred that the substrate be wet with water whenthe reaction takes place. Ionic or non-ionic surface active agents maybe utilized in any aqueous medium used in applying the reagents.

In the presence of the above systems, it is believed that theethylenically unsaturated compounds react with the keratin fibers,although the mechanism of the reaction is by no means completelyunderstood. It is known, however, that when acrylonitrile or anotherethylenically unsaturated compound of the desired class is applied tokeratin fibers in the presence of one of the above initiating systems,the resulting keratin fibers increase considerably in weight, and thereacted compounds cannot be readily removed by extraction techniquesutilizing solvents for the homopolymers of such compounds. It is,consequently, believed that the reacted compounds to a large extent arecovalently bonded to the keratin fiber molecule. Similar effects areobtained, however, when the reacted compound is otherwise bonded to thefibers, but these compounds are generally extractible and, therefore,not as permanent. Where permanence is not essential, this type bondingis suitable though not as desirable as are the covalently bondedcompounds.

The reaction of the above monomers or their derivatives with keratinfibers may be conducted at room temperature, although temperaturesbetween 40 and 60 C. are generally preferred. A temperature in excess ofabout 100 C. is generally not preferred since thermal activation ofmonomers becomes appreciable and undue degradation of some of thecomponents of the preferred catalyst system, the redox system, occurs atthis elevated temperature. In general, such conditions as concentrationsof the reagents, pH, time and temperature of reaction may be modified tosuit the individual circumstances, while still providing the desireddegree of reaction.

The fibrous substrate may be exposed to the monomer in vapor, liquid oremulsion form. Exposure to the vapors of the monomers is convenientlycarried out by entraining the vapor in an oxygen free gas, such asnitrogen, and then interposing the substrate in a stream of the gas andvapor. Inert volatile liquids, such as water or an alcohol, may be mixedwith the compound being vaporized. Similarly, the fibrous substrate maybe immersed in a liquid system, either solution or emulsion type,containing the desired amount of monomer.

Any desired apparatus may be used to apply one or more of the aboveclass of ethylenically unsaturated compounds to keratin fibers, such asby'padding, spraying or the like, but preferred apparatus includesforced-flow equipment, such as disclosed in the copending applicationSer. No. 243,671, now U.S. Pat. 3,291,560. With this apparatus, thedesired systems can be repeatedly forced back and forth through keratinfibers at controllable flow rates to provide particularly good reactionresults.

While the process of this invention is particularly adapted to fibroussubstrates composed essentially of keratin fibers, particularly thosecomposed entirely of wool fibers, it is also applicable to substrateswherein synthetic or natural fibers are blended with keratin fibersandto blends with other keratin fiberssuch as mohair, alpaca, cashmere,vicuna, guanaco, camels hair, silk, llama and the like. The preferredsynthetic fibers include polyamides, such as poly(hexamethyleneadipamide), polyesters, such as poly(ethylene terephthalate), andacrylic fibers such as acrylonitrile, homopolymers or copolymers ofacrylonitrile containing at least about 85% combined acrylonitrile, suchas acrylonitrile/methyl acrylate (85/ 15) and cellulosics, such ascellulose acetate and viscose rayon. Of the natural fibers which may beblended with the keratin fibers, cotton is preferred. In any such blend,the keratin fibers treated in accordance with this invention arepreferably present in at least a major proportion.

In order to provide acceptable fabric aesthetic and physical properties,it is preferred to conduct the desired reaction on keratin fibers inrelatively loose form, i.e., prior to processing into yarn as in top,tow, roving, sliver and the like. Fabrics produced from these fibersthrough conventional processing techniques are characterized by softerhandle, better drapeability and tear strength, among other improvements,even though more ethylenically unsaturated compound is present in thefabric than is possible when a fabric per se is treated.

Improved fabrics are obtained even when the keratin fibers are in theform of yarn at the time of treatment, but fabric aesthetic propertiesare less desirable in this embodiment. The reacted fibers may bemechanically crimped, as with gear crimping apparatus, heated or not,prior to processing into fabric. In many instances, this will facilitatefiber processing, as well as provide a more luxurious fabric.

In the following examples, the best modes, as presently known, ofpracticing the invention are shown.

EXAPLE I Into a 2-lb. Gaston County package dye machine are mounted 800gms. of wool top, 400 gms. being mounted on each of 2 bobbins which areplaced on the single perforated spindle of the dye machine. Afterscouring by passing through the package dye machine an aqueous solutioncontaining 0.5% on the weight of wool of Surfonic N95, a non-ionicsurface active agent, and 1.5% on the weight of wool of glacial aceticacid for 20 minutes at 140 F., the wool is rinsed in water at F. for 15minutes. Deionized water is used in preparing all aqueous media in thisexample. An aqueous solution made up from 7400 cc. of H 0 containing1.74 gms. of

(0.03% Fe+++) based on wool weight, 12.2 cc. of a 50% solution of H 0(50/1 molar ratio of peroxide based on Fe+++) and 40 cc. of concentratedH 50 is circulated through the machine and wool top. After ten minutes,960 gms. of acrylonitrile (enough for 120% pickup) is added into therecirculating catalyst system. The resulting system has a pH of 1.3 andprovides a liquor/wool ratio of 11/ 1. This system is held at 75 -85 F.and forced back and forth through the fibers at a flow-rate of about 34gallons per minute for 15 minutes, at a cycle of 3 minutes outsidein and2 minutes inside-out, after which the temperature is raised to 120 F. bypassing steam through the heat jacket of the package dye machine. Thereaction is continued at this temperature for an additional minutes.

The wool top is then removed from the machine and found to haveincreased in weight uniformly by 95.5%. After boiling in dimethylfonnamide for one hour, the wool top is found to weigh approximately thesame.

A 4-inch length of this top, weighing about 90 milligrams, with 2 t.p.i.inserted twist, is mounted as a tight loop with a S-mil. diameter pianowire. The loop is then pressed at about 100 lbs. per square inch at 300F. for

-3 minutes in a hydraulic press. The pressed loop is then placed inwater heated to 140 F. for 20 minutes and dried. The included angleformed by the creased top is measured at 44. A similar length ofuntreated wool top of the same weight pressed in the same manner retainsan angle of 162. In this measurement, the lower the number the greaterthe crease retention of the creased fibers.

This procedure is repeated to obtain wool top having .a pickup of 75%reacted acrylonitrile. The retained crease angle of this sample is 61when tested in water at 100 F.

EXAMPLE II Utilizing the technique of Example I, methyl methacrylate isadded to wool top to the following levels: 69%, 90%, 111% and 128%.After creasing as in Example I and testing in water at 100 F., the wooltop retains crease angles of 70, 40, 46 and 54, respectively.

When the procedure of Example I is repeated to apply 84% by Weight ofmethyl acrylate on the wool top, the wool top retains a crease angle of87 after testing as in Example I.

EXAMPLE III Onto the perforated beam of a 100-lb. capacity Gaston Countypackage dyeing machine are wound 63 lbs. of wool top. The beam is thenmounted over the perforated spindle, the machine is closed and the woolis scoured for 30 minutes at 140 F. with 80 gallons of deionized watercontaining 429 gms. of acetic acid and 149 gms. of Synfac 905, anon-ionic wetting agent containing a nonylphenol ethyleneoxide (1/9-1/2molar ratio) condensation product. During the scouring operation, as inall succeeding operations in this example, the liquids are forcedthrough the wool in a cycle of 4 minutes outside-to-inside, 6 minutesinside-to-outside. After scouring, a redox catalyst system composed of63 gms. of Fe(NO and 429 gms. of 50% H 0 and 75 gallons of Wateradjusted to a pH of 1.35 with 12 lbs. of H 80 and maintained at 100 F.,is passed through the wool for 20 minutes. The flow rate of the systemthrough the wool is measured at about gallons per minute. Nineteen lbs.of styrene are then added to the recirculating liquid and this system isrun for 20 minutes at 120 F. The remaining monomer (57 lbs. styrene) isthen added to the system continuously until expended-about 1% hours. Thereaction is continued for an additional 3 hours after which the machineis drained and the wool is washed with water at 75 F. for 20 minutes.

As a finishing operation, the wool is then impregnated with 80 gallonsof Water containing 4% Arquad 16-50, a hexadecyl trimethylammoniumchloride lubricant, and 1% Synfac-905 for 40 minutes at 125 F. The wooltop treated in this manner is found to have increased in weight by100.6%. After creasing and testing at 100 F. as in Example I, the wooltop retains a crease angle of 62. When this procedure is repeated toapply 93% of reacted styrene to the wool and the test is conducted at140 F., the retained crease angle is 56. When this procedure is repeatedto apply 58% by weight of reacted styrene on the wool top, the retainedcrease angle is 78.

EXAMPLE IV Wool top is treated as in Example III to an increase inweight of 30%, 75%, 80% and 125% by weight of reacted styrene. Theresulting wool top is processed in the yarn and woven into fabric.Samples from each of these 4 fabrics are folded over and pressed in afolded condition in a Hoifman press using 30 seconds steam, 30 secondsbake and seconds vacuum. The samples are all creased to a very sharpdegree and then heated in water at 140 F. for minutes, air dried in anopen condition and rated visually. The fabric sample containing byweight of styrene shows a very slight crease, whereas a controlcontaining no styrene shows no crease whatsoever. The samples containing75 and 80% styrene show good creases after this treatment, whereas thesample containing 125% styrene shows an excellent crease even after thewater treatment.

Fabrics produced from the acrylonitrile reacted wool and methylmethacrylate reacted wool illustrate creasa-bility and creaseretentivity.

A pair of trousers produced from fibers containing 80% by weight ofreacted styrene exhibits excellent settability and crease retentivitywhen creased and tested as before. These trousers are purposelyre-creased in a different location. No double-crease appears afterre-creasing or testing in water at 100 F.

That which is claimed is:

1. A process of preparing garments having a creased configuration whichis durable to the effects of Wetting with water and which is capable ofbeing removed under conditions of heat and pressure similar to thoseemployed in the forming thereof comprising reacting keratinic fibers toa level between about and 130% by weight of said fibers with anethylenically unsaturated compound having, in polymer form, a glasstransition temperature greater than about 50 C. or with twoethylenically unsaturated compounds having, in copolymer form, a glasstransition temperaturev greater than about 50 C.; forming a fabric fromsaid modified fibers; preparing a garment from said fabric and pressingsaid garment in a creased configuration at a temperature in excess ofthe glass transition temperature of the compound system utilized.

2. The process of claim 1 wherein the fibers are reacted to a levelbetween about and by weight.

3. The process of claim 1 wherein the garment prepared is a pair oftrousers.

4. A garment produced by the process of claim 1.

References Cited UNITED STATES PATENTS 3,031,334 4/1962 Lundgren 117-1412,406,412 8/ 1946 Speakman et al.

2,940,869 6/ 1960 Graham.

2,956,899 10/1960 Cline.

3,005,730 10/1961 Pardo 117-141 3,008,920 11/ 1961 Urchick.

3,083,118 3/ 1963 Bridgeford 8-128 GEORGE F. LESMES, Primary Examiner I.CANNON, Assistant Examiner U.S. Cl. X.R.

